Electrodeposited stable nano structured aluminum manganese alloys exhibit an exceptional combination of high hardness and tensile ductility. In addition to the combination of high hardness and tensile ductility, the alloys are approximately the same density as other aluminum alloys. This combination of high strength, ductility, and light weight make it an ideal structural material for applications such as armor, aircraft, sporting equipment, and other applications where a light weight high strength ductile material would be of benefit.